Air-temperature control for carburetors



. 1,567,805 F. c. MO CK AIR TEMPERATURE CONTROL FOR CARBURETORS Dec. 29 1925- Filed April 5, 1920 2 smu -shed 1 Dec. 29 1925- F'. C. MOCK AIR TEMPERATURE CONTROL 1 0R CARBURETORS Filed April 5 1920 2 Sheets-Sheet 2 Patented Dec. 29, 1925.

UNITED STATES PATENT OFFICE.

FRANK C. MOCK OF CHICAGO, ILLINOIS, ASSIGNOR 'IO STROMBERG MOTOR DEVICES COMPANY. OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AIR-TEMPERATURE CONTROL FOR CAR BURETORS.

Application filed April 5, 1920. Serial No. 371,436.

To all whom it may concern:

Be it known that I, FRANK C. Mocx, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Air-Temperature Controls for Carburetors, of which the following is a full, clear', concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates tointernal combustion engines, and more particularly to improved means for controlling the temperature of air taken into the carburetor intake pipe for mixture with the liquid fuel delivered to the carburetor for forming a combustible mixture.

It is well known that the present quality of heavy, and in some cases light, hydrocarbon fuel is such that heat to a greater or less extent must be applied to the fuel before the same can be efliciently burned in the resent prevailing type of internal combustion engines. It is also well known that the power of a motor, with correct carburation, varies as the density of the air contained in the charge, and that the air density and consequent proportion of air in the mixture varies with the absolute tem- Eerature. This is due to two conditions,

rst, the fuel decreases in viscosity upon a rise in temperature, permitting the fuel to flow faster through a given et, secondly, the quantity of air or proportion of air to gas decreases as the air temperature rises, consequently enriching the mixture. Therefore, it is highly desirable that the temperature of the air and the mixture be kept uniform, and as moderate as possible, as the power of the motor will, up to a certain point, increase as the temperature of the charge is reduced. This condition is so pronounced that an increase in temperature of 50 degrees F. from a predetermined temperature range will result in a 10% loss of ower.

n the ordinary type of motor vehicle the air taken in by the carburetor is drawn from inside the hood and is consequently heated b entering through the radiator. It is a c aracteristic feature of the water in the cooling system that its temperature does not vary directly with the atmospheric temperature; that is, with a given cooling system the temperature of the cooling medium, which is usually water, will be approximately 50 deg. F. when the atmospheric temperature is 20 deg. F., or 30 deg. higher than that of the atmosphere. In warm weather, with an atmospheric temperature of 90 deg., the cooling medium often reaches a temperature of 180 deg. or 90 deg, greater than that of the atmospheric temperature. Therefore, the problem of maintaining a mixture of maximum power giving quality at all temperatures, means that it is necessary to cope with changes in temperature ranging from zero Fahrenheit (at starting.) to 150 deg. F. or higher under normal running conditions. Such a temperature range represents a great change in power. These conditions are further complicated because provide a device, which will handle the eavier hydrocarbon fuel now in general use underallv conditions; will maintain a temperature adequate to handle these fuels in all seasons of the year; and to provide a device which will maintain a practically uniform temperature in the carburetor so that the carburetor need not be manually regulated in the general use of the car, except possibly at starting. I prefer to accom lish the above objects by a structure set orth in detail later, the same embodying means for taking air into the carburetor from a point external of the engine hood when it is desired to cool the air. entering the carburetor and to heat another source of air by the engine exhaust when it. is desired to warm the carburetor. The two sources of air to the carburetor are automatically controlled by a thermostatic unit sensitive both to changes in atmospheric temperature and pressure. For heating the air passing to the carburetor ll providean improved form of hot-spot against which the incoming air is caused to impinge. v

lit is a further object of my invention to combine with the foregoing a heated surface or hot spot in the intake manifold for fogging the mixture after passage from the Figure 4 is a fragmentary view, partly in elevation and partly in section showing a modified form of the invention.

Referring in detail to the embodiment of my invention shown in Figure 4, 10 designates the frame of a motor vehicle on which is mounted a motor 11 of any standard type. The cylinders 12 of the motorare joined by a cylinder block 13 with which the intake manifold 14 and the exhaust manifold 15 communicate.

Asuitable carburetor 16 supplies the combustible mixture through the neck 17 to the intake manifold, and exhaust heat from the exhaust manifold may be supplied to the neck 17 by a conduit 18 for vaporizing the heavier particles of fuel. I prefer to employ a structure at this point similar to that of my improved fogging device embodied in prior application, serial No. 334,895, filed October 31, 1919. The heating device is here designated 19. The carburetor 16 is provided with a suitable air inlet 20 and is also provided with the usual throttle lever 21.

The dash 22 and the radiator 21 are arranged as' in the standard type of motor vehicle, the engine hood 23 extending between the same and being of the standard hinged 2 or 4-part construction.

Essentially my invention resides in the provision of two entrances for air to the carburetor, one taking air from a hot-s ot or the like, and the other taking air rom without the hood, preferably from a point just between the sides of the hood and the front mud guard, the air at this point being of higher velocity and depositing less dust than elsewhere; in combination with the heating device 19 for the mixture.

In keeping with the foregoing, I provide the carburetor pipe 24 connected with the menace carburetor air intake 20, the pipe 24 having a branch 25 extending downwardly and cut through the side of the hood 23, said pipe 24 having a second branch 26, extending up wardly to an air heater 27 the structure of which is best shown in Figures 2 and 3.

In constructing this heater it is important that the thickness of the hot wall be small in comparison to the area presented to the heat of the exhaust as l have found that in starting the exhaust temperature arises. to within 50 degrees of its normal temperature fifteen seconds after starting the m0- tor, and therefore, it is desirable to comm'unicate this heat as quickly as possible to the air delivered to the carburetor.

I prefer to construct the heater by forming an opening 28 in the wall of the exhaust manifold 15' and close this opening with a sheet of metal forming a heat conducting Wall 29 provided with a plurality of corrugations 30 projecting into the path of travel of the exhaust gases, the branch pipe 26 having a lip or extension 31 projecting over the wall 29 and terminating short of the forward end thereof to form an opening 32 permitting entrance of air from within the hood. Machine screws 33 or the like may be employed to secure the extension 31 and wall 29 in place.

I provide automatic means for controlling the entrance of air to the carburetor through one or the other, or of said branches, which means comprises preferably a pair of butterfly valves, one, 34, controlling the branch 25 and the other, 35, controlling the branch 23. The valve 35 is provided with operating arm connected by means of a link 37 to one arm 38 of a bell crank lever 39 carried the shaft of the other valve 34 The other arm 40 of the bell crank lever is connected by means of a link 41 to a lever 42, 'fulcrumed at 43 to a housing' 44 carried by the carburetor and communicating with the air intake pipe thereof. Within the housing 44 is mounted a thermostatic unit provided with an extension46 engaging the lever 42. The unit is adapted to act against the tension of the spring 47 in accordance with the temperature of air inthe pipe 20.

In normal operation and starting at zero temperature the thermostatic unit would be set so that in normal position when the motor is at rest the valves 34 and 35 would be in the positions shown in Figure 1. Thus upon starting, the maximum heat obtainable through the heater 27 would be delivered to the air taken in through the opening 32 and conducted to the. carburetor. As the temperature of the air inside the pipe 24 and the mixture passing through the carburetor rises the thermostatic unit 45 will expand imparting motion in a rearward direction to the lever 42, which in turn opens the valve 34: and closes the valve 35, more or less depending upon the degree of temperature change. Thus an accurate and efficient constancy of temperature of the mixture supplied to the motor is had.

In Fi ure 4 a modified form of the invention is s own wherein it is intended to control the .temperatureof the air sup lied to the carburetor in accordance with t e temperature of the mixture after leaving the carburetor and while enroute through the intake manifold to the engine.

In this form of the invention the intake manifold is provided with an opening 48 in one arm thereof, said opening being closed by a plate 49 which carries a bi-metallic thermostatic unit 50, the free end of which is oppositely engaged with a slidable pin 51, the outer end of the pin engaging a lug 52 carried by a lever 53 fulcrumed at 54 on said plate 49. The lever 53 is connected by means of a link 55 to one arm of the bell crank lever 56, said lever 56 being connected to the valve 35 in the branch 26. The other arm of the bell crank lever 56 is connected by means of a link 57 to a lever 58 carried by the shaft of the valve 34. In this form of the invention the thermostatic unit is adapted to operate to control the admittance of hot or cold air to the carburetor by controlling the positions of the valves 34 and 35. I

From the foregoing it will be seen that a marked improvement in the control of the air temperature as supplied to the carburetor and ultimate result is obtained by the device of my invention. Upon the source of carburetor air largely depends the power obtained and the efiiciency of the motor. As

ointed out hereinbefore, the device of my lnvention compensates for changes in temperature within and without the hood. Thus rather than supply the carburetor in summer time warm air from inside the hood, I provide means whereby this sup 1y may be obtained from outside the hood; and, in

winter, when the warmth of the mixture, at

least at starting, is highl desirable, the de viceautomatically furnis es air at a moderate temperature and maintains this air at such temperature throughout the different ran es 0 engine speed. The device will ena Ie the modern ty e of internal combustion en 'ne to han e the present heavy fuels with the maximum of power obtainable, and will also reduce the tendency to knock under heavy load in warm weather. The device will, as well, eliminate the necessity of changing the carburetor adjustment for extremes of temperature encountered, and also will do away with much of the dash control manipulat on now required.

Minor alterations may be made in the structural arran ement of parts to permit the adaptation o the device to various styles of an arrangement of engine parts, and therefore I do not limit my invention. to the details of construction shown, but reserve the right to make such changes as may be required when reducing the evice to practice.

I claim:

1. In combination with an exhaust manifold, anair heater comprising a conduit having connection with the exhaust manifold a wall between said conduit and the mamfold, said wall having corru ations projecting into the exhaust manifold and an extension on said conduit terminating short of one end of said wall to ermit the entrance of air into said con uit in contact with said wall.

2. In combination, an exhaust manifold having an o ening in the side wall thereof, a corrugate plate set into said opening, a cover plate extending over the outside of said corrugated plate, said corrugated plate and said cover plate defining an air chamber therebetween, and a conduit for drawing heated air from said air chamber.

In witness whereof, I hereunto subscribe my name this 2nd da of A ril, A. D., 1920.

IRA K C. MOCK. 

